Comparative vibrational spectroscopic studies, HOMO–LUMO and NBO analysis of 5,7-dibromo-8-hydroxyquinoline and 5,7-dichloro-8-hydroxyquinoline based on Density Functional Theory

https://doi.org/10.1016/j.molstruc.2011.07.022Get rights and content

Abstract

Comparative studies of the Raman and infrared spectra, the geometry, frequency and intensity of the vibrational bands of 5,7-dibromo-8-hydroxyquinoline (DBHQ) and 5,7-dichloro-8-hydroxyquinoline (DCHQ) were obtained by using Density Functional Theory calculations (DFT) with B3LYP functional and 6-311++G** basis set. The effects of bromine and chlorine substituents on the vibrational frequencies of 8-hydroxyquinoline have been investigated. The assignments have been proposed with aid of the results of normal coordinate analysis. Coupling of vibrations have been determined by calculating potential energy distributions (PEDs). The molecular stability and bond strength was investigated by applying the Natural Bond Orbital analysis (NBO). The other molecular properties like Mulliken population analysis, thermodynamic functions and polarizabilities of the title compounds have been reported. The calculated HOMO and LUMO energies show that charge transfer occur in the molecules. Information about the size, shape, charge density distribution and site of chemical reactivity of the molecules has been obtained by mapping electron density isosurface with electrostatic potential (ESP).

Highlights

Hydroxyquinoline derivatives are used as antimalarial and anticancer drugs. ► Vibrational bands of DBHQ and DCHQ were obtained by the B3LYP/6-311++G**. ► NBO, Mulliken charges and other parameters have been reported. ► A comparison with the IR and Raman spectra of DBHQ and DCHQ has been reported. ► The electronic properties, HOMO and LUMO energies and ESP also studied.

Introduction

Quinoline, is an aromatic nitrogen compound characterized by a solid-ring structure contains a benzene fused to pyridine at two adjacent carbon atoms. Quinoline derivatives are used as catalyst, corrosion inhibitor, preservative and as solvent for resins and terpenes. They are used in transition-metal complex catalyst chemistry for uniform polymerization and luminescence chemistry. They are used as antifoaming agent in refinery field. Quinaldine, 2-methylquinoline are used as an anti-malarial and preparing other anti-malarial drugs. It is used in manufacturing oil soluble dyes, food colorants, pharmaceuticals, pH indicators and other organic compounds. Hydroxyquinoline and its derivatives are bacterial inhibitor and precursor of a number of anti-malarial and anticancer drugs [1], [2].

Literature survey reveals that detailed interpretations of the infrared spectra have been reported on halogen substituted hydroxy quinoline [3]. But the results based on quantum chemical calculations and FT-IR, FT-Raman spectral studies, the HOMO–LUMO and NBO analyses on 5,7-dibromo-8-hydroxyquinoline (DBHQ) and 5,7-dichloro-8-hydroxyquinoline (DCHQ) have no reports. This inadequacy observed in the literature encouraged us to make this theoretical and experimental vibrational spectroscopic research based on the structure of molecules to give a correct assignment of the fundamental bands in experimental FT-IR, FT-Raman spectra. Along with the vibrational spectra, the electrostatic potential should help us to understand the structural and spectral characteristic and bioactivity of compounds of this class.

In the present work, we have attempted to study the HOMO–LUMO, NBO analysis, the thermodynamical functions and polarizability of DBHQ and DCHQ by using B3LYP level of theory throughout with the 6-311++G** basis set implemented in the Gaussian 09 program suite [4]. Geometries obtained from DFT calculation were then used to perform NBO analysis.

Section snippets

General method

The fine samples of DBHQ and DCHQ were obtained from Lancaster Chemical Company, UK and used as such for the spectral measurements. The FT-Raman spectra of DBHQ and DCHQ were recorded using 1064 nm line of Nd:YAG laser as excitation wave lengths in the region 3500–100 cm−1 on thermo electron corporation model NEXUS670 spectrometer equipped with FT-Raman module accessory. The FT-IR spectrum of the title compounds were recorded in the region 4000–400 cm−1 on Perkin Elmer Spectrophotometer in KBr

Geometric structure

The optimized molecular structures of the DBHQ and DCHQ belong to C1 point group symmetry with numbering schemes is presented in Fig. 1, Fig. 2, respectively. The existences of two rotational isomers between pyridine and hydroxyl groups (O-cis and O-trans) in DBHQ and DCHQ have been demonstrated. The energy values of cis and trans for DBHQ −5624.3432 hartrees (−14766714.319 kJ/mol) and −5624.3435 hartrees (−14766714.5572 kJ/mol) and for DCHQ are −1396.5023 hartrees (−3666517.0792 kJ/mol) and

Mulliken population analysis: Mulliken atomic charge

Mulliken atomic charge calculation [44] has an important role in the application of quantum chemical calculation to molecular system. Atomic charges affect dipole moment, polarizability, electronic structure and more properties of molecular systems. The total atomic charges of DBHQ and DCHQ obtained by Mulliken population analysis with 6-311++G** basis set are listed in Table. 5. From the result it is clear that the substitutions of Br, Cl and OH atoms in the heteroaromatic ring leads to a

Conclusion

A complete vibrational assignment for DBHQ and DCHQ have been proposed, aided by the B3LYP method using 6-311++G** basis set and PED analysis. FT-IR and FI-Raman spectra of DBHQ and DCHQ molecules have been recorded. The optimizations of the relative orientation of the bromine, chlorine, and hydroxyl group of the DBHQ and DCHQ, respectively leads to two forms, O-cis and O-trans with O-trans being more stable in both DBHQ and DCHQ. The theoretically computed wavenumbers were found good agreement

References (48)

  • S. Sagdinc et al.

    Spectrochim. Acta, Part A

    (2007)
  • V.P. Gupta et al.

    Spectrochim. Acta, Part A

    (2006)
  • C.V.L. Narasihma Rao et al.

    Indian J. Pure Appl. Phys.

    (1981)
  • Khaled Bahgat et al.

    Cent. Eur. J. Chem.

    (2007)
  • M.J. Frisch et al.

    GAUSSIAN 09, Revision A.02

    (2009)
  • A.D. Becke

    J. Chem. Phys.

    (1993)
  • C. Lee et al.

    Phys. Rev. B

    (1988)
  • A. Frisch, A.B. Neilson, A.J. Holder, GAUSSVIEW user Manual, Gaussian Inc., Pittsburgh, CT,...
  • P. Venkata Raman Rao et al.

    Spectrochim. Acta Part A

    (2002)
  • P. Pulay et al.

    J. Am. Chem. Soc.

    (1979)
  • A.E. Reed et al.

    J. Chem. Phys.

    (1985)
  • A.E. Reed et al.

    J. Chem. Phys.

    (1985)
  • A.E. Reed et al.

    J. Chem. Phys.

    (1983)
  • J.P. Foster et al.

    J. Am. Chem. Soc.

    (1980)
  • Cited by (30)

    • Keto-enol tautomerism, spectral (infrared, Raman and NMR) studies and Normal coordinate analysis of 4-Methyl-2-hydroxyquinoline using quantum mechanical calculations

      2022, Journal of Molecular Structure
      Citation Excerpt :

      The Raman spectrum displayed a weak line at 349 cm−1 associated with that computed at 338 cm−1 (ωB97XD) which represent δip C=O vibration mode (ν37, A′) although it is significantly mixed with δip C‒CH3 (ν38, 29% PEDs), see Table 1. The out-of-plane butterfly mode for keto-MQO (ν53, A″) give rise to a weak Raman line appeared at 288 cm−1 which is consistent with that reported for 5,7-dichloro-8-hydroxyquinoline, 234 cm−1 [69] however higher than that observed for adenine at 193 cm−1 [31]. For fused pyridine ring, three ring twist fundamentals (ν55‒ν57, A″) were allocated to wavenumbers predicted/observed at 176/179(m), 145/139(w-m) and 97/103(m), respectively (Fig. 1A).

    • 5,7-Dibromo-8-hydroxyquinoline dissolved in binary aqueous co-solvent mixtures of isopropanol, N,N-dimethylformamide, 1,4-dioxane and N-methyl-2-pyrrolidone: Solubility modeling, solvent effect and preferential solvation

      2020, Journal of Chemical Thermodynamics
      Citation Excerpt :

      No. is 521-74-4. 5,7-Dibromo-8-hydroxyquinoline has effective antibacterial, antiprotozoal, antiamoebic, antifungal bacteriostatic and fungistatic activities, particularly used in treating the intestinal amebiasis [14–18]. As well as its pharmaceutical importance, 5,7-dibromo-8-hydroxyquinoline is also used in spectrophotometric study and solvent extraction process [19,20].

    View all citing articles on Scopus
    View full text